480v 3 phase forklift charging station

[ryan7097]

I have an existing 480v 3 phase 50a breaker traveling approx 325 ft to a unistrut grid where 3 existing forklift Battery charging stations with 10a fused 3 ph 480v disconnects are located. they are in a trough tapped feeding each disconnect then to isolated 20a/480v twist lock outlets. My question is if each of the 3 chargers is a 36v dc setup can I simply add three more and tap them in the trough or do I need to run a separate 3 ph 480v 50a circuit and tap those out and copy what has been done already. My main purpose is to add 3 more charging stations for a total of 6. Any info would be greatly appreciated. Furthermore, should I install a ventilation system as well, and if so what kind? Again thanks for your thoughts.

 

[Coppersmith]

What does the nameplate on the actual charger say is the amperage used? Six chargers using 8.33 amps would 100% load your 50 amp circuit. If the chargers use more than 8.33 amps each, then six chargers would overload the circuit. This assumes the load is not considered continuous which would limit amp load to 80%. I'll let others debate that aspect.

I would also be concerned about voltage drop on such a long run. The higher the amp draw, the more voltage drop it will have. Can the chargers tolerate low voltage? Does low voltage cause the charger to draw more amps?

 

[Hv&Lv]

Battery chargers aren’t continuous loads but I agree, we need amp draw from nameplate.
6 is probably going to be over 50A
im assuming these are three phase chargers or single phase?

 

[LarryFine]

Welcome to the forum. Do you know the actual conductor size, and just in case, the conduit size?

If the existing wires are large enough, you might look into upsizing the feeder breaker.

 

[Barbqranch]

Another question is how will the chargers be used. Will they all be started at the same time, or are they spread out during the day. At least our forklift charger tapers down pretty quickly, and I can imagine without knowing for sure, that if the voltage drop were a little too much, it would simply extend the initial charge phase.

 

[ryan7097]

Battery chargers aren’t continuous loads but I agree, we need amp draw from nameplate.
6 is probably going to be over 50A
im assuming these are three phase chargers or single phase?

After plugging in the forklifts on the existing 3- 480v charging station the draw was:
11.5A on unit 1 = 23 A
5.6A on unit 2 = 11.2 A
9.2A on unit 3 = 18.4 A
If times it by 2 I should have an accurate amperage draw of what Six(6) 480v 3PH Chargers would Draw
52.6A is What I Have Calculated as Needed.
Now the interesting thing here is the Previous Electrician that installed the existing 3 Charging stations used #2 AWG THHN for Voltage Drop.
Can I either Swap out the 3ph 50A Breaker for a 60A or/and from the feeders in the troth install a 3ph 480 Sub Panel then Feed each of 6 charging stations with individual 20A/480v 3ph Breakers Hence Individually protecting each Charger with are 36v DC.
Thanks to all, your time is appreciated!

 

[ryan7097]

Welcome to the forum. Do you know the actual conductor size, and just in case, the conduit size?

If the existing wires are large enough, you might look into upsizing the feeder breaker.

After plugging in the forklifts on the existing 3- 480v charging station the draw was:
11.5A on unit 1 = 23 A
5.6A on unit 2 = 11.2 A
9.2A on unit 3 = 18.4 A
If times it by 2 I should have an accurate amperage draw of what Six(6) 480v 3PH Chargers would Draw
52.6A is What I Have Calculated as Needed.
Now the interesting thing here is the Previous Electrician that installed the existing 3 Charging stations used #2 AWG THHN for Voltage Drop.
Can I either Swap out the 3ph 50A Breaker for a 60A or/and from the feeders in the troth install a 3ph 480 Sub Panel then Feed each of 6 charging stations with individual 20A/480v 3ph Breakers Hence Individually protecting each Charger with are 36v DC.
Thanks to all, your time is appreciated!

 

[ryan7097]

Another question is how will the chargers be used. Will they all be started at the same time, or are they spread out during the day. At least our forklift charger tapers down pretty quickly, and I can imagine without knowing for sure, that if the voltage drop were a little too much, it would simply extend the initial charge phase.

They would be used sporadically through the day, most likely charged all or some at night when warehouse is closed

 

[petersonra]

Can I either Swap out the 3ph 50A Breaker for a 60A or/and from the feeders in the troth install a 3ph 480 Sub Panel then Feed each of 6 charging stations with individual 20A/480v 3ph Breakers Hence Individually protecting each Charger with are 36v DC.
Thanks to all, your time is appreciated!

I think you are on the right track but I don't think you are allowed to use the measured current draw. I think you need to use whatever the nameplate current says. #2 is good for 115 Amps so you have plenty of room to upsize the feeder breaker.

 

[ryan7097]

Welcome to the forum. Do you know the actual conductor size, and just in case, the conduit size? #2 Awg Copper THHN Indoor Warehouse.
Thank you, sir.

If the existing wires are large enough, you might look into upsizing the feeder breaker.

After plugging in the forklifts on the existing 3- 480v charging station the draw was:
11.5A on unit 1 = 23 A
5.6A on unit 2 = 11.2 A
9.2A on unit 3 = 18.4 A
If times it by 2 I should have an accurate amperage draw of what Six(6) 480v 3PH Chargers would Draw
52.6A is What I Have Calculated as Needed.
Now the interesting thing here is the Previous Electrician that installed the existing 3 Charging stations used #2 AWG THHN for Voltage Drop.
Can I either Swap out the 3ph 50A Breaker for a 60A or/and from the feeders in the troth install a 3ph 480 Sub Panel then Feed each of 6 charging stations with individual 20A/480v 3ph Breakers Hence Individually protecting each Charger which is 36v DC.
Thanks to all, your time is appreciated!

Sorry if I'm double posting as I'm still getting the hang of this.

 

[ryan7097]

this is what id like to do:

 

[robertd]

After plugging in the forklifts on the existing 3- 480v charging station the draw was:
11.5A on unit 1 = 23 A
5.6A on unit 2 = 11.2 A
9.2A on unit 3 = 18.4 A
If times it by 2 I should have an accurate amperage draw of what Six(6) 480v 3PH Chargers would Draw
52.6A is What I Have Calculated as Needed.
Now the interesting thing here is the Previous Electrician that installed the existing 3 Charging stations used #2 AWG THHN for Voltage Drop.
Can I either Swap out the 3ph 50A Breaker for a 60A or/and from the feeders in the troth install a 3ph 480 Sub Panel then Feed each of 6 charging stations with individual 20A/480v 3ph Breakers Hence Individually protecting each Charger with are 36v DC.
Thanks to all, your time is appreciated!

You multiply the currents on the left by two to get the currents on the right. Does each charger get just 2 phases, or all 3 phases?